Psalms 19:3-4

Psalms 19:3-4. There is no speech nor language, where their voice is not heard, Their line is gone out through all the earth, and their words to the end of the world.

All men must hear God’s voice in nature if they are only willing to do so.

Paul wrote to the Romans, "The invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead;" so that those who will not see "are without excuse."